Fin straightening hand tool



w. M. WEBB 2,91

FIN STRAIGHTENING HAND TOOL Filed Oct. 20, 1958 Nov. 17, 1959 ATTORNEY INVENTOR.

United States Patent FIN STRAIGHTENING HAND TOOL William M. Webb, Tyler, Tex., assignor to General Electric Company, a corporation of New York Application October 20, 1958, Serial No. 768,488

2 Claims. (Cl. 81-15) The present invention relates to a hand tool for straightening and correcting the spacing of the exposed edges of the thin metallic fins of heat exchanger coils such as are used in refrigeration and air conditioning systems.

: Heat exchangers of the type with which the tool of the present invention is to be employed for fin straightportions thereof are frequently damaged during shipment of the heat exchanger or during normal installation and use thereof. If these fins become bent or overlapped over a substantial area of the heat exchanger, air flow through the heat exchanger decreases thereby ilimiting thev efficiency of-the entire air conditioning unit of which the heat exchanger forms a part. In addition,

the appearance of a damaged heat transfer surface. is .muchimproved upon by straightening the fins.

. Accordingly, it is a primary object of the present invention to provide. a fin straightening tool for straightening and correcting the spacing of the exposededge portions of the thin metallic fins of a heat exchanger.

Further objects and advantages of the present invention will become apparent from the following description and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

In accordance with the present invention there is provided a straightening tool comprising a handle and a blade assembly including a plurality of spaced parallel co-extensive blades rigidly secured to the handle. Each of the blades has a flat bottom edge of a length equal to at least the distance between centers of adjacent heat exchanger tubes and preferably about twice that distance so that this portion of the tool which is adapted to engage some of the heat exchanger tubes when the blades of the assembly are inserted between the heat exchanger fins will bridge and readily ride over the tubes during advancement of the tool through a damaged fin area. Each of the blades is also provided with a sloping top edge forming with the bottom edge a tapered end portion which during sliding advancement of the tool penetrates beneath and asserts a lifting force on a bentover fin edge portion for progressively straightening the bent fin during advancement of the tool. A particular feature of the present invention is the provision of a sufiicient number of blades in the blade assembly so that the assembly will be of a width greater than the normal depth of the fin edge portions. By this construction, a side-to-side rocking action of the tool during advancement thereof through a damaged fin area will cause the tool to pivot about the bottom edge of one or the other of the outer blades in the blade assembly supported by 2,912,888 Patented Nov. 17, 1959 heat exchanger tubes thereby imparting a vertical movement of the remaining blades to progressively lift and straighten deformed fin sections in progressive stages such that cutting and tearing of the fins can be avoided.

For a better understanding of the invention reference may be had to the accompanying drawing in which:

Fig. 1 is a side elevation view of the tool of the present invention; and

Fig. 2 is a front view of the tool illustrating the preferred manner in which the tool of the present invention is employed for straightening the heat exchanger fins.

Referring now to the drawings, the tool of the present invention is illustrated in its application to a heat exchanger comprising a plurality of parallel refrigerant tubes 1 which are in spaced apart relationship and are provided with a plurality of closely spaced fins 2 extending transversely to the refrigerant tubes 1 and having edge portions 3 extending outwardly from these tubes. During handling orshipment of the heat exchanger, these thin edge portions 3 which are relatively fragile are easily bent over as indicated by the numeral 4. Since this curling or bending over of the exposed edge portions 3 of the fins obstructs air flow through the damaged area, the efliciency of the heat exchanger is correspondingly decreased. Hence it is desirable that the fins 2 and particularly the exposed edge portions 3 be spaced and properly aligned for maximum efficiency.

The fin straightening tool of the present invention comprises a handle 6 including one or more slots 7 forming a convenient hand grip in which the lower portion 8 of the handle forms a protective knuckle guard to prevent accidental contact with the sharp edges of the fins during use of the tool.

Since the thickness and spacings of the fins vary with different heat exchangers, the tool of the present inventionis illustrated as being provided with two ditferent jblade' assemblies 9 and 10 which differ primarily only in the relative spacing of the blades 11 comprising each of the blade assemblies. In both of these blade assemblies which are rigidly secured to the handle 6, the center-to-center spacing of the blades is about the same sliding advancement of the tool over the tubes 1 to pene-.

trate beneath the bent over portions 4 of the fins. As the blade assembly is advanced through a damaged section of the heat exchanger, this upwardly sloping top edge portion 14 of the blade bears up under and progressively straightens the bent fin portions 4.

In order to obtain an effective and more controllable lifting action of the bent over portions 4 of the fins without tearing of the fin material, the tool of the present invention is particularly designed to have a blade assembly width such that by a side-by-side rocking action of the tool with one or the other of the outer blades 16 of the blade assembly in contact with the tube or tubes 1 will, through a lever action, cause the remaining blades in the assembly to pivot upwardly about the bottom edge of the tube-contacting blade 16 to impart a more gradual and more controllable straightening action to the bent fin sections. For this purpose the blade assemblies should be of a width equal to at least the depth of the fin edge portions or in other words sufiicient so that the blades spaced from an outer blade 16 will during the rocking action of the tool impart an essentially vertical lifting action rather than twisting movement to the fins in engagement therewith.

By providing a plurality of blades with the outer blades of the blade assembly spaced as hereinbefore described, straightening of a damaged fin area is obtained most effectively and with little chance of tearing or cutting the relatively thin fin material by advancing the tapered end portions of the blades through the damaged area and simultaneously rocking the tool from side-to-side during advancement. The straightening forces applied by this rocking action are more easily controlled and are less likely to cause further damage to the bent fins than those which can be applied merely by advancing the tapered end portion 15 of the blades through the damaged area. When the damage is severe as for example when the blades are bent in such a manner that the bent portion of each fin overlaps the bent portion of an adjacent fin, it is advisable to advance the tool rather slowly and obtain most of the straightening action through the short side-to-side rocking movements of the tool rather than by through a straight advancement of the tool which may cause the sloping top edge 14 or the end 15 of a blade to penetrate and cut or tear the fins contacted thereby.

While there has been shown and described a particular embodiment of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is intended by the appended claims to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A tool for straightening deformed fins of a heat exchanger of the type including a plurality of spaced parallel tubes provided with spaced parallel fins extending transversely of said tubes and having edge portions extending outwardly from said tubes, said tool comprising a handle and a blade assembly comprising a plurality of spaced parallel coextensive blades rigidly secured to the handle, at least the outermost blades of said assembly having a flat bottom edge of a length equal to at least the center-to-center distance between adjacent heat exchanger tubes and adapted to be supported by some of said tubes when said blades are inserted between adjacent heat exchanger fins, all of said blades having a sloping top edge forming with said bottom edge a tapered end portion on said blades which is adapted upon sliding advancement of said tool over said tubes to penetrate beneath a bend-over fin edge portion, the distance between said outer blades of said blade assembly being greater than the normal depth of said fin edge portions, whereby side-to-side rocking of said tool with the bottom edge of one or the other of said outer blades supported by said tubes effects a lifting and straightening of the deformed fin sections by the remaining blades during advancement of the tool.

2. A tool for straightening deformed fins of a heat exchanger of the type including a plurality of spaced parallel tubes provided with spaced parallel fins extending transversely of said tubes and having edge portions extending outwardly from said tubes, said tool comprising a handle and a blade assembly comprising a plurality of spaced parallel coextensive blades rigidly secured to said handle each of said blades having a fiat bottom edge of length equal to at least about twice the center-to Center distance between adjacent heat exchanger tubes and adapted to be supported by some of said tubes when said blades are inserted between adjacent heat exchanger fins, each of said blades having a sloping top edge forming with said bottom edge a tapered end portion adapted upon sliding advancement of said tool over said tubes to penetrate beneath a bent-over fin edge portion, the distance between the outer blades of said blade assembly being greater than the normal depth of said fin edge portions, whereby side-to-side rocking of said tool with the bottom edge of one of said outer blades supported by said tubes causes the remaining blades to lift and straighten the deformed fin sections during advancement of said tool.

References Cited in the file of this patent UNITED STATES PATENTS 1,505,210 Lee Aug. 19, 1924 2,222,081 Leigh Nov. 19, 1940 2,314,034 De Roo Mar. 16, 1943 2,607,249 Johnson Aug. 19, 1952 2,618,185 Fechter Nov, 18, 1952 2,818,757 Pille Jan. 7, 1958 2,839,958 Bundy' June 24, 1958 

